Combined gas washing and sludge recovering apparatus



Oct. 9,, 1934. J. P. GRILL! 1,976,392

COMBINED GAS WASHING AND SLUDGE RECOVERING APPARATUS Filed June 6, 1932 4 Sheets-Sheet 1 0a 9, 1934. P, G ILLI 1,976,392

COMBINED GAS WASHING AND SLUDGE RECOYERING APPARATUS Filed June 6. 1932 4 Sheets-Sheet 2 Oct. 9, 1934.

J. P. GRILL] 1,976,392

COMBINED GAS WASHING AND SLUDGE RECOVERING APPARATUS Filed June 6, 1932 4 Sheets-Sheet 3 9 fizz/62502 Get. 9, 1934. J GRILL] 1,976,392

COMBINED GAS WASHING AND SLUDGE RECOVERING APPARATUS Filed June 6. 1932 4 Sheets-Sheet 4 Patented Oct. 9, 193

PATENT @FFICE GORBINED GAS WASHING: AND SLUDGE RECUVERING APPARATUS John P." Grilli, Ehicago, Till. -Application June ii, 1932, Serial No. 61$,dh9

5% Claims.

This invention relates to apparatus for the separation and recovery of suspended solids from hot gases, and one of the objects is to effect a. high degree of cleaning by the use of a heated t3 washing medium.

A further object is to provide means within the washer for continuously removing the washing medium and the solid particles which have been intercepted by form of a concentrated sludge.

A further object is to obtain hot and sumciently clarified water for re-use in the washing apparatus.

It iswell known that in the washing of gases, any fluid at or near its boiling point is a more efficient washing medium than when cold,'due

to the much lower surface tension and viscosity oi the washing medium when at a temperature at or near its boiling point, nevertheless it has I heretofore not been practical to use such hot water for the washing, in the conventional typeof apparatus, of gases of low value, such as blast furnace gases.

Various gas washing methods have been tried, using recirculated hot wash water as the washing medium, but noneof them has heretofore been commercially successful.

One of the difficulties encountered has been the depositing of the solid matter precipitated from the hot washing liquid, in the spraying apparatus, and in the feed pipes and valves, thereby interfering with the distribution of the water, and preventing the effective and eflicient operation of the washer.

Hotclean wate, deriving its heat from an external source, could be used as the hot washing -medium, but the cost of such external heat would result in increasing the cost of hot gas washing to such a point that nothing would be gained over the present methods which use cold water as a washing medium.

The settling or precipitation of sludge from a highly heated liquid is a difllcult problem, on account of the rapid cooling which takes place in the usual settling tanks, such as Dorr thickeners, owing to the large exposed surfaces. Such a. method of cooling sets up convection currents, owing to the differential temperature between the hot water and the surrounding air, causing agitation which retards settling.

In the present invention all of these difficulties and objections have been overcome, and I am able to fine-clean dirty gases continuously, at the same time continuously separating the sludge 55 from the cleamng or wash water in the same apit and recover them in the paratus, preferably a tower, in which is carried out this improved cleaning process.

In this process the hot washin stage is followed by a cooling stage, the latter being preferably embodied in a second tower in which the cooling of the gases and the condensing of the moisture from the gases takes place.

In the case of blast furnace gas, which, before washing, has been brought down to a content of from 2 to 20 grains of dust per cubic foot by passing it through one or more large dust catchers; it has a vapor content varying between 30 and grains per cubic foot at temperatures usually ranging between 300 and 500 degrees F.

This gas enters the hot washing tower and is forced through a zone of hot mist created by a suitable spray creating means, preferably one or more revolving spray cones.

In passing through these spray cones the heavier dust particles are removed from the gas. The heat of the gas and the water vapor in the gas cause a portion of the spray water to be flashed into steam. I The gas and steam are then forced through any desired type of cleaner, but preferably a cleaner embodying one or more spray discs" which have beater bars attached thereto, and to which cleaner the hot wash water is applied.

The combined action of the revolving beater bars and the hot water results in fine-cleaning of 85 the gas,

The hot dirty wash water collects in the bottom of the tower where a series of spaced superimposed truncated cones are arranged. These cones are submerged beneath the surface of the water and in which the solids will settle out, forming a. sludge at the bottom, which may be continuously or intermittently withdrawn from the apparatus. a

The rate of wi hdrawal of the sludge can be 95 controlled so as to obtain the most desirable concentration of the sludge, and at the same time the cleanest water for re-circulation.

The cleaned wash water is then recirculated by a recirculation pump provided for that purpose in the first stage.

, The separation of the water from the sludge is accomplished in a very effective manner by the action of these multiple separation cones. The top cone protects the clarifying water against agitation which would result from the splashing of the wash water falling from above, while the remaining cones cause the velocity of the flow of the clarifying water to progressively decrease as it ascends in counterflow to the sludge, toward 110 the outlets at the upper ends of the cones, the solids sliding down on the walls of the cones, which latter are at a suflicient angle to prevent accumulation.

The gas is then led to the second stage where it is forced in counterflow to cold water, preferably through a series of hurdles and spray zones, and if desired, finally through another spray disc with revolving beater bars.

In this second stage, moisture is condensed, and with it dust particles and fumes are separated.

This improved method and apparatus will be more clearly understood when taken in connection with the accompanying drawings in which Figure 1 is a view partly in vertical section and partly in diagram of an apparatus by means of which this improved method may be carrier into operation.

Figure 2 is a vertical, sectional view on an enlarged scale of the upper portion of the washing apparatus.

Figure 3 is a vertical, sectional view taken on an enlarged scale of the lower portion or sludge removing part of the apparatus.

Figure 4 is a horizontal detail sectional view taken .on line 4-4, Figure 2.

Figure 5 is a horizontal sectional view taken on line 5-5, Figure 3. 7

Referring more particularly to the drawings, the numeral 10 designates generally a casing of any desired size and configuration and of any desired height, and constitutes a vertical tower within which the washing and sludge removing portion of the mechanism is arranged.

The tower is supported in any suitable manner such as by means of supports 11 and the bottom thereof is preferably conical as at 12 so as to direct the deposit of foreign matter or sludge through an opening 13 to be removed through a pipe or outlet 14, to a suitable filter (not shown), the sludge discharge outlet being controlled by means of a valve 15.

Arranged within the upper part of the casing 10 and supported in any suitable manner preferably by means of a member 16, is a casing 17, the external diameter of which is considerably less than the internal diameter of the adjacent portion of the casing 10 so as to form a passage 18 therebetween. This casing 17 may be of any desired diameter and of any desired height, the bottom 19 of which preferably inclines towards the diametric center thereof and is provided with an opening 20 at the center preferably surrounded by a depending flange 21 so that any foreign matter deposited in the casing 17 will pass out of the opening 20.

Arranged within the casing 17'is another casing 22 which is of an external diameter considerably less than the internal diameter of the adjacent portion of the casing 17, and the space between the casings 17 and 22 is closed by means of a member 23 arranged adjacent the top of the casing 22. The lower end 24 of the casing 22 is preferably slightly tapered and terminates short of the bottom 19 of the casing 17, the tapered portion of the casing 22 operating to direct foreign particles toward the center of the bottom 19. Openings 25 are provided in the wall of the casing 17 above the member 23 so as to form communication between the space 18 between the casings 10 and 17 and the interior of the casing 17 above the member 23. The top of the casing 22 is-open as at 26 so that gases flowing up through the passage 18 will enter the casing 17 above the member 23, through the openings 25 and will then be directed downwardly through the casing 22 out of the bottom thereof and thence upwardly to an outlet opening 27 with which an outlet pipe 28 for the gases communicates.

The casing 17 is closed at its top as at 29 and projecting thereinto through the closed top and at the center of the casing is a tubular member 30 which preferably projects into and terminates in proximity to the top of the casing 22. The external diameter of the tubular member 30 is considerably less than the internal diameter of the casing 22 and arranged within the tubular member 30, but spaced therefrom to form a passage 31, is a bearing 32, in which is journaled a shaft 33 to which is secured one or more beater members 34.

Any form'of beater members suitable for this purpose may be employed, such for instance as the beater member disclosed in United States Patent 1,766,588, issued June 24, 1930, to Edwin M. Bassler, Patent 1,767,628, issued June 24, 1930, to E. Von Maltitz, or Patent 1,766,267, issued June 24, 1930, to H. A. Strain, or application of Herman A. Brassert, et al., Serial Number 576,288, filed November 20, 1931, suflice it to say that the beater members are preferably provided with a body portion formed of a disc with spaced bars 35,-between which the gas and water are forced to pass so as to be beaten up and thoroughly intermixed, and at the same time thrown out by centrifugal force against the'wall of the casing 22.

In the form of the invention shown in the drawings two of these beater members 34 are arranged within the casing 22 and are separated from each other for a substantial distance. Arranged between the upper and lower beater members and supported by and encompassing the inner periphery of the casing 22 is a trough 36 having downwardly inclined portions 37 which communicate with an opening 38 disposed adjacent the diametric center of the next lowermost beater member and encompassing the shaft 33, so that any liquid or particles deposited in the trough 36 will be conducted through the portions 37 to be delivered to the disc of the next lowermost beater member 34.

The shaft 33 with the beater and spraying members 34-35 carried thereby, is adapted to be rotated at any desired speed and in any suitable manner, but preferably by means of a motor 39 connected with the shaft 33, the motor being mounted upon a suitable support 40.

The upper portion of the casing 22 preferably projects above the point of junction of the member 23 as at 41 to form a dam for the water which accumulates upon the member 23 so that the water flowing thereover and passing between the periphery of thesprayer and beater members 3435 and the adjacent portion of the wall of the casing 22 will form a seal between the periphery of the beater member and the casing to prevent the escape of therethrough.

Water is supplied to the beater members from the supply pipe 42 which has communication as at 43 with the passage 31 between the tubular member 30 'and the bearing 32 of the shaft 33, and a valve 44 may be provided in the supply pipe for controlling the amount of water delivered'into the tubular member 30. Water flowing through the pipe 42 when the valve 44 is opened, will be delivered from the tubular memgases pasing downward cones of the series 52. The

masses ber 30 on to the disc 34 of the uppermost beater or sprayer member.

The member 16 forms a closure for one end of the space or passage 18 between the casings 16 and 17, and the gas which passes up such space will be delivered therefrom through the openings 25 in the wall of the casing 10 above the uppermost heater and sprayer member 34-435 and will be forced downwardly with the water through the uppermost beater and sprayer member, at the same time being thoroughly mixed with the water.

The water will then gravitate to the bottom oi the casing 22 and into the bottom at the casing 17 to be discharged therefrom through the opening so into a spraying device preferably in the form of spaced superposed truncated cones l5, any number oi which may be provided, of any desired or suitable diameter and of any desired height. The external diameter of these cones 45, however, are of a size considerably less than the internal diameter of the casing 10, and the internal diameter is of a size considerably greater than the opening 20 of the bottom 19 or the casing 17. These cones are secured to the shaft 33 for rotation therewith and the uppermost cone &5 is arranged in close proximity to the lower end oi the flange or collar 21 on the bottom 19.

Disposed below the bottom 19 of the casing 1'? is a partition or flange 46 which is supported by the wall of the casing 10 and inclines downwardly towards the diametric center of the casing terminating in an opening 47 encompassing the cones i5, and the diameter of the opening 4': is considerably greater than the external diameter of the cones 45. Arranged beneath the opening 4'7! within the casing 10 and mounted upon suitable supports 48 is a pan or receptacle 49 of an external diameter considerably .less than the internal diameter of the casing 10, and the shaft 33 passes through the bottom or the pan or tray 49. This tray or pan is of any desired height but preferably of a height that the top of the wall thereof will be d above the lower open portion of the lowermost cone 45. The shaft 33 also passes through a bearing 50 'in suitable supports 51 beneath the supports 48 and secured to the shaft 33 and spaced for a considerable distance below the cone sprayers 45 is another set. of similar cone sprayers 52. A partition 53 similarto the partition 46 is supported by the wall of the casing 16- and inclines downwardly terminating in an opening 54 encompassing the uppermost opening 54 being of a diameter considerably greater than the external diameter of the cones 52. A pan or tray 55 mounted upon suitable supports 56 and of a diameter considerably greater than the diameter of .the cones 52 is arranged below the uppermost cone of the series 52, the wall thereof terminating above the bottom open end of the lowermost cone of the series 52.

Shields 57 and 58 are arranged around the lower opening of the lowermost cone or the series 45-52 so as to prevent water from being thrown outwardly by these cones at the bottom of the series and to insure the rising of the water within the cones to be thrown by centrifugalforce over the tops or uppermost edges of the cone.

The dirty gas to be cleaned passes into the tower through an inlet opening 59 arranged below the lowermost series of cones 52 and will flow upwardly in a tortuous passage in the direction indicated by the arrows passing through the partitions 53 the truncated and 46 into the space or passage 18, thence upwardly and through the openings 25 to be directed downwardly into the top of the casing 22 through the beater or sprayer members 34-35 thence out of the bottom of the casing 22 into the casing 17 and thence out of the outlet opening 27 into the pipe 28. In this passage of the gas it meets with the water and mist and the heavy particles will be removed and will gravitate with the water into the bottom section of the casing or tower it toward the conical bottom 12.

Arranged in the lower section oi the tower and below the gas inlet opening 59, are a series of concentrically arranged and spaced truncated cones 6llythe apices of which are arranged lowermost and these cones are spaced for any desired or suitabl. distance from each other, the bottom 12 of the casing 10 being preferably shaped to co incide with the shape oi the truncated cones 60.

foreign matter and Leading Erom the uppermost edges of the cones 66 are outlet pipes 61, any number of which may be provided for each cone and these outlets are arranged around the periphery of the cones. The upper extremities of the pipes 61 are arranged at the same level to establish a predetermined water level in the cones. A plurality of junction boxes 62 may preferably be provided, into which the respective overflow pipes 61 discharge. These junction boxes are preferably connected by pipes 61 and an outlet pipe 63 is preferably connected with one of the junction boxes to convey away the water discharged from the cones 60.

The water from the upper part of the tower flows downwardly into the lower portion in which cones 60 are arranged and fills the lower portion of the tower together with the truncated cones to the water level established by the outlets of the pipes 61 and the wash water overflowing from the cones into the junction boxes 62 will be withdrawn therefrom by means of the water circulation pump 64, suitably operated to withdraw the wash water and deliver the same into the supply pipe 42 to be discharged back into the top of the tower and into the passage 31 in the member 30. 1

Thus it will be seen that the wash water will be takenirom the bottom of the tower and recirculated back to the top of the tower. The foreign matter or sludge forming in the truncated cones 60 will settle upon the walls of the cones and will flow through the openings in the bottom thereof out of the opening 13 into a chamber 65 to flow through the pipe 14 to the filter. when desired, a suitable valve 66 may beopened for discharging the sludge or material out of the chamber 65.

Connected with the chamber 65 is an emergency overflow preferably in the form of a pipe 67 having a controlling valve 68 therein. This pipe 67 connects with the header or junction box 69 "arranged at an elevation higher than the outlet openings of the pipes 61 so that when in case or an emergency, the water level should rise above the predetermined limit. the valve 68 may be opened to permit excess water to flow out of the pipe 67 through the header or junction box 69 and out of the discharge pipe '10.

The water which ascends between the cones 60 and overflows at the upper ends thereof into the pipes 61 and the cleaned gas flowing out the pipe 28 from the top of the tower will be conducted to a cooling and condensing tower designated generally by the reference numeral '11 and delivered into the bottom is separated from the sludge thereof. This cooling and condensing tower is 0! any desired construction, but preferably of the construction disclosed in the application of Herman A. Brassert, et a1., Serial Number 576,288, filed November 20, 1931. Suflice it to say that .the vapor and steam ladened gases from the tower or casing 10 are discharged into the inlet 72 adjacent the lower end or bottom thereof, water being supplied through the pipe 73 from any suitable source and conveyed by means of a pipe 74 to rotary spraying discs 75 preferably constructed similar to the spraying discs 8435. The supply pipe 73 also delivers water to the spraying nozzles 76 while overflow water from the spraying discs 75 which will collect in the cone shaped member 75', will pass through a pipe 77 to be delivered into a pipe 78 and conveyed to additional spraying nozzles 79. Arranged beneath the spraying nozzles 76 are suitable baflies or hurdles 80 and similar baflles or hurdles 81 are arranged beneath the spray nozzle 79, and through which baffles or hurdles the water from the nozzles will pass in counter-current to the flow of the gas upwardly in the tower 71. A screen 82 is preferably arranged adjacent the inlet 72. The water precipitating or flowing downwardly in the tower or section 71 will accumulate in the bottom 83 of the tower 71, and three outlets are preferably provided for the bottom of the tower 71. To that end a chamber 84 may be provided which has an outlet 85 leading to a waste overflow 86, this outlet being controlled by a valve 87, an emergency draw off 88 controlled by a valve 89, and an outlet from which leads a pipe 90, which is connected to the pipe 63 of the first unit, a valve 91 being provided in the pipe for controlling the pipe connection. This pipe 90 serves to supply make .up water to the primary washing unit or tower 10 as during the operation of the device it has been found that water will be lost in the hot stage by passing out with the sludge, also by a portion of the water being flashed into steam as well as the water which is carried by entrainment with the gas into the second stage of the apparatus. Therefore, to make up or resupply such losses of the water, the make up supply may be taken from the bottom of the tower or unit 71, through the pipe 90 and delivered into the pipe 63 to be circulated or forced through the pipe 42 back into the top or the first unit of the apparatus.

In starting the operation of the apparatus, the truncated cones 60 are filled with water to the overflow level and the pump 64 is started. The hot dirty gases are then admitted into the tower or unit 10 through the inlet opening 59 and during the operation of the device the dirty hot water will collect and accumulate in the cones 60 at the bottom of the tower or unit.

As the water is very hot, the degree of settling will be rapid, and as the discharge outlet 61 of each of the cones 60 is considerably higher in elevation than their inlet, the effect of gravity on the foreign particles or sludge is to cause it to settle or precipitate near the bottom outlet of the truncated cones.

During the operation of the device and as the shaft 33 is being rotated, the water delivered through the pipe 43 into the passage 31 will fall upon the uppermost mixer and beater 34-35. Gas coming in contact with this water will be mixed by the beater with the water and the mixed gas and water will then flow downwardly to the next lowermost beater and mixer 34-45, the gas passing out of the casing 22, thence changing its direction of flow and passing into the casing 17 to flow out of the discharge outlet 27.

The water falling out of the casing 22 will pass through the opening 20 in the bottom of the casing 17 to be delivered to the uppermost cone spray mixer 45, where it will be thrown outwardly and upwardly and again collected upon the partition 46, flowing from the partition 46 through the opening 47 into the pan 49. The cone sprays 45 act as a pump and lift the water from the pan 49 by centrifugal force, cause a. continuance of the recirculation of the water, excess water flowing over the edge of the pan 49 on to the partition 53 where the operation will be repeated by the lowermost series of cone spray discs 52, that is the water flowing over the edge of the pan 49 will pass into the cone sprayers 52 to be thrown out by centrifugal force or the partition 53 and will thence flow downwardly into the pan 55 where it will be picked up by centrifugal action by the cone sprays 52 and thrown outwardly to be delivered into the bottom of the tower.

The gas flowing in the direction of the arrows indicated in. Figure 2 and counter-current to the fiow of water, will be thoroughly washed and all of the heavy particles and foreign matter will be removed therefrom and will be carried by the water by gravity and intothe lower section of the tower unit where the truncated cones 60 are arranged, precipitation from the water occurring in the truncated cones and the water passing off as clean wash water and into the pipe 63 to be recirculated by the pump back to the top of the tower.

The construction of the bottom of this apparatus is such that agitation or any trouble resulting from convection currents in the hot water will be avoided, and a much hotter water temperature will result.

The solid particles in the water which have been removed from the gases are continuously removed from the bottom of the apparatus as sludge, and the overflow from the uppermost ends of the truncated cones will be returned to the circulation pump through the pipes 63 and reused as wash water, being discharged back into the tower or unit 10 at the top thereof through the pipe 42.

Any loss of water in the apparatus which passes out with the sludge, or which is flashed into steam, or which is carried over by entrainment of the gases into the second stage of the apparatus, may be resupplied as make up water and taken from the bottom of the tower or unit 71, through the pipe 90.

While the preferred form of apparatus for carrying this invention into operation has been herein shown and described, it is to be understood that various changes may be made in the details of construction and in the combination and arrangement of the several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new is:

1. A gas washing apparatus having a gas inlet and a gas outlet, means for admitting a washing medium, the washing medium and solids being collected in the apparatus, the'hot dirty gases being admitted into the apparatus above the water level therein, stationary nested and spaced elements for preventing agitation of the washing medium during the settling operation, a portion of the said elements operating to settle the solids from the washing medium, means for separately discharging from the apparatus the clarified washing medium and the solids separated therefrom, and means for cooling and condensing water vapors in the washed gas.

2. A gas washing apparatus embodying a hot washing stage and a cold washing stage, a plurality of superposed truncated cones in the hot washing stage for collecting the washing medium and foreign particles and for settling the solids from the washing medium to clarify the latter, the hot dirty gases being admitted into the apparatus above the uppermost cone and above the water level in the apparatus, and means for separately removing the clarified washing medium and the solids therefrom; one of said cones and the last recited means operating to prevent agitation of the water during settling, caused by changing gas pressure.

3. A gas washing apparatus embodyi a hot washing stage and a cold washing stage, a plurality of superposed truncated cones in the hot washing stage for collecting the washing medium and foreign particles and for settling the solids from the washing medium to clarify the latter, the hot dirty gases being admitted into the apparatus above the uppermost cone and also above the water level in the apparatus, means for separately discharging clarified washing medium and solids from the settling cones, one of said cones and the last recited means operating to prevent agitation of the water during settling, caused by changing gas pressures, means for cold staging the washed gas which passes from the 'hot stage, to condense vapor in the gas, andmeans for circulating water from the cold stage back to the hot stage as makeup water for losses of the washing medium occasioned in the hot stage, and for preventing the building up of soluble matters in the recirculated water.

4. A gas washing apparatus having a closed circuit hot water washing and humidifying stage, stationary nested spaced elements within the apparatus to settle hot dirty water, the hot dirty gases being admitted into the apparatus above the water level therein, one of said elements operating to prevent agitation of the water during settling, means to discharge clarified hot water, means to separately discharge the solids, means to recirculate clarified hot water, means for condensing the watervapor from the gas about the dust particles therein to produce droplets whereby the latter will form vehicles for removing fine dust from the gas, and means to eliminate the entrained water in the gas.

5. A gas washing apparatus having a gas inlet and a gas outlet, means for admitting wash water, means for intimately mingling the water and gas, the wash water and solids accumulating in the apparatus, means for separating the water and the solids, the last recited means embodying superposed spaced trimcated cones, the dirty gases being admitted into the apparatus. above the uppermost cone and above the water level in the apparatus, the uppermost cone serving to maintain the accumulated wash water against agitation by the splashing of wash water thereinto and for preventing agitation by convection currents caused by the hot gas striking the colder water, the remaining cones operating to cause the velocity of flow of the clarifying water to progressively decrease as it ascends counterfiow to the solids, towards the water outlet, and means for separately removing the accumulated wash water and the solids removed therefrom.

6. A gas washing apparatus having a gas inlet and a gas outlet, means for admitting wash water, means for intimately mingling the water and gas, the wash water and solids accumulating in the apparatus, means for separating the water and the solids, the last recited means embodying superposed spaced truncated cones, the dirty gases being admitted into the apparatus above the uppermost cone and above the water level in the .apparatus, the uppermost cone serving to maintain the accumulated wash water against agitation by the splashing of wash water thereinto and for preventing agitation by convection currents caused by the hot gases striking the colder water, the remaining cones operating to cause the velocity of flow of the clarifying water to progressively decrease as it ascends counterfiow to the solids, towards the water outlet, means for separately removing the accumulated wash water and the solids removed therefrom, means for recirculating the clarified wash water back into the apparatus, and means for supplying make-up water to replace the water lost in the operation of the apparatus and for preventing the building up of soluble matters irrthe recirculated water.

7. A gas washing apparatus having a gas inlet and a gas outlet, means for admitting wash water, means for intimately mingling the water and gas, the wash water and solids accumulating in the apparatus, means for settling the solids in the water, the last recited means embodying superposed spaced truncated cones, the dirty hot gas being admitted into' the apparatus above the uppermost cone and above the water level in the apparatus, means whereby agitation caused by changing gas pressures in the settling stage will be avoided, the uppermost cone serving'to maintain the accumulated wash water against agitation by the splashing of wash water thereinto and for preventing agitation by convection currents caused by the hot gas striking the colder water, the remaining cones operating to cause the velocity of flow of the clarifying water to progressively decrease as it ascends counterfiow to the solids, towards the water outlet, means for separately removing the accumulated wash water and the solids removed therefrom, means for cold staging by water sprays the clarified gas to condense water and vapor therein, and means for furnishing, to the hot stage, make-up water from the discharge of the cold stage to take care of losses and to prevent the building up of the soluble content of the water. 1 8. A gas washing apparatus having a gas inlet and a gas outlet, an inlet for admitting a washing medium, the washing medium and solids being collected in the apparatus, means for settling the solids from the washing medium, the last recited means embodyin a plurality of superposed spaced and concentrically arranged inverted truncated cones operating to change the direction of flow cf the washing medium at different points of flow of the washingmedium in the apparatus, a portion of said cones operating to prevent agitation of the washing medium during the settling operation, and means for separately dis-' charging from the apparatus the clarified wash JOHN P. cam-r. 

